maven项目报错Non-resolvable parent POM for com.example:demo-1:0.0.1-SNAPSHOT: Failure to transfer org.sp_[fatal] non-resolvable parent pom for com.example:

Project build error: Non-resolvable parent POM for com.example:demo-1:0.0.1-SNAPSHOT: Failure to transfer org.springframework.boot:spring-boot-starter-parent:pom:1.5.2.RELEASE from https://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced. Original error: Could not transfer artifact org.springframework.boot:spring-boot-starter-parent:pom:1.5.2.RELEASE from/to central (https://repo.maven.apache.org/maven2): repo.maven.apache.org: nodename nor servname provided, or not known and ‘parent.relativePath‘ points at no local POM

解决方法：
参考stack overflow：
I‘ve also encountered a lot of error when creating a new STS project 
for the first time. This seems to be happen only if I don‘t have any 
Maven repository or haven‘t launch/use Maven before. In my case, 
I solve this by launching Maven command from command line manually. 
Try to ‘cd‘ to the project directory that contains pom.xml and call 
mvn that comes with STS from there.
1
2
3
4
5
6
7
8

sql
cd c:\users\name\sts-projects\projectname
c:\programs\springsource\apache-maven-3.0.3\bin\mvn compile

Then, open STS, right click on project name, select ‘Maven‘, ‘Update Project…‘ Select on ‘Force Update of Snapshots/Releases‘. Don‘t select ‘Offline‘.
翻译过来就是：打开终端，进入项目的根目录，然后使用 maven bin 目录下的 mvn 编译命令编译一下（也就是mvn compile），完成之后右键项目 选择Maven，之后选择Update Project 即可。（个人理解就是清空项目的jar包仓库，之后更新重新下载）
原文：https://www.yuanmas.com/info/obyn9QB7aK.html